I haven't watched the series yet so I'll base my review solely on the movie.

There's a element of surprise for me since I haven't watched the drama, so I don't know much of the characters' personalities. At the end I was taken aback.. like WTF .. I like how the movie is not totally biased on which country is the hero of the movie. I find the portrayal of the characters by the actors so cool and excellent, though there were times I wonder if they speak Japanese or Korean coz the leads voices were so low. But that add points to their bad ass portrayals. I grinned so much when there's interaction between Japanese and Korean characters.
Overall, I enjoyed the movie and I can't find a point of disappointment in the movie. If you want a movie with full of intense scenes and  Jap.Kor  agents'   together  in a movie ,then this is a must watch for you.